The overburden consists of permeable sands and gravels ranging in thickness from less than 10 feet to approximately 28 feet. A till layer generally is found below the sands and gravels in contact with the bedrock. The till layer varies between 0 and 25 feet in thickness. Many large boulders were found in the overburden during excavation of the contaminated soils in 1994.
Targeted Environmental Media:
 Dense Non-aqueous Phase Liquids (DNAPLs) - Fractured Bedrock
An estimate of plume size from a five year review map shows a length of approximately 1,100 feet and a width at its widest of 770 feet.
Major Contaminants and Maximum Concentrations:
- Acetone (37,000 µg/L)
- Tetrachloroethene (14,000 µg/L)
- Trichloroethene (50,000 µg/L)
- 1,2-Dichloroethene (83,000 µg/L)
- 1,1,1-Trichloroethane (35,000 µg/L)
- Vinyl chloride (8,000 µg/L)
- Methylene chloride (16,000 µg/L)
- 2-Butanone (MEK) (62,000 µg/L)
- 2-Pentanone (6,800 µg/L)
- Toluene (33,000 µg/L)
No technologies selected.
- Pump and Treat
Comments:
Monthly average pumping rates for the eight extraction wells have consistently been maintained at the target of 48 gpm since November 1999. Dissolved contaminants have a downward trend. Bedrock monitoring wells continue to have concentrations of chlorinated solvents in the tens of thousands ug/L.
5 ug/L for TCE, methylene chloride, and PCE. MCLs for lead, vinyl chloride, p-dichlorobenzene, and 1,1-dichloroethene.
Bedrock monitoring wells continue to have concentrations of chlorinated solvents in the tens of thousands ug/L.
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